— Where does the president of the U. S. live?

— ______________[ ]

A. The Buckingham Palace.

B. The Palace Museum.

C. The White House.

仪器仪表装配时常用的钳口工具可分为尖嘴钳、偏口钳和（）。

A、老虎钳

B、扁嘴钳

C、镊子钳

D、钢丝钳